Patent document 1 discloses that a compound represented by a formula and a salt thereof, encompassing compound A and a salt thereof, have a superior gonadotropic hormone-releasing hormone antagonistic action and can be used, for example, as a prophylactic or therapeutic agent for hormone dependent diseases, together with the production method of the compound.
Patent document 2 discloses a preparation containing a compound represented by the above-mentioned formula and a salt thereof, which characteristically contains an organic acid and shows improved oral absorbability.